Safety attachment for internal-combustion engines



May 6, 1930.V M. K. BARNARD SAFETY ATTACHMENT FOR INTERNAL COMBUSTION ENGINES Filed Nov. 50, 1927 2 Sheets-Sheet l May 6, 1930. I M. K. BARNARD 1,757,353

SAFETY ATTACHMENT FOR INTERNAL COMBUSTION ENGINES Filed Nov. 30, 1927 2 Sheets-Sheet 2 INVENTOR.

V, )4 TToRNEYs Patented May 6, 1930 UNITED STATES PATENT OFFICE MAXWELL K. BARNARD, SEMINOLE, OKLAHOMA, ASSIGNOR TO GYPSY OIL COM- PANY, OF TULSA, OKLAHOMA, A CORPORATION OF OKLAHOMA SAFETY ATTACHMENT FOR INTERNAL-COMBUSTION ENGINES .Application filed NovemberSO, 1927. Serial No. 236,811.

This invention relates to improvements in internal combustion engines and particularly to a safety device for controlling the operation of said engine.

While the invention is applicable to various types of engines, the present illustration of a two-cycle gas engine Will suffice for purposes of fully disclosing the preferred embodiment of the invention.

lVhen an engine is operating in locations Where gas or gasoline vapors are presentV in the atmosphere, the engine may rather readily develop` excessive speed due to an explosive mixture entering the chamber` in which the fuel is mixed preparatory to being delivered to the engine cylinder. This may even occur When the gas line has been closed or the ignition system rendered inoperative as the high temperature created by the compression of the gas in the cylinder will effect an explosion or ignition thereof. Such incidents or conditions often occur and have resulted in rather serious accidents so that it may be said that in the absence of means for controlling the flow of explosive mixture to the cylinders and the development of excessive engine speeds, life and property are endangered.

An object of the present invention, therefore, is the provision of means for cutting off the flow of gaseous mixtures to the engine cylinders when the engine operates above a predetermined speed. Such means, in the present instance, preferably close not only the gas supply line but they also prevent explosive mixtures gaining access to the cylinders through the air intake pipe or line of the fuel mixing chamber of the engine.

More specifically, the `invention contemplates normally inoperative means sensitive to the vibrations of the engine for closing both the air and gas inlets of the mixing chamber, said means being adjustable Whereby they may be rendered operative Whenever the engine operates in excess of a predetermined speed.

lVith these and other objects in view the invention consists in certain novel details of construction and combinations and arrangements of parts all as Will hereinafter be more fully described and the novel features thereof particularly pointed out in the appended claims.

Tn the accompanying draWings,-

Figurel is a sectional view longitudinally of the cylinder of a commercial type of two cycle gas engine7 parts of the engine proper being shown diagrammatically.

Fig. 2 is a top plan view ofthe cover of the tuel mixing chamber;

Fig. 3 is a vertical sectional View through the mixing chamber;

Fig. L1 is a plan View of the valve in said chamber.

In the type of engine illustrated, fuel is.

supplied by the gas pipe 10 to a gas chamber 11 and air is supplied to a chamber 12 through pipe 13. Through ports 14 the gas escapes to the mixing chamber 15 and air flows to said chamber from air chamber 12 through ports 16. The iovv of gas and air through said ports may be controlled by separate valves or closures but in the present instance such closures are formed integrally With one another, constituting one unitary valve 17 carried on a .valve stem 18 slidable in a bore centrally of the gas chamber 11.

As the operation of the engine proper is Well understood, suflice it to say that assuming that the mixture in explosion chamber 19 of the cylinder has just been exploded by a spark from spark plug 20, piston E21 is driven toward the opposite end 22 of the cylinder, compressing the air-gas mixture which has been drawn through the ports 141, 16, the suction created by the previous movement of piston 21 to compress the mixture in explosion chamber 19 prior to its ignition having' elevated valve 17 to open ports 14, 16. Piston 21 moves toward end 22 of the cylinder,

first uncovering exhaustport 23 allowing the vexpanded burnt gases to escape to atmosphere. Inlet port- 24 is then uncovered allowing a fresh charge of the fuel mixture to rush from end 22 of the cylinder, Where it has been compressed, to explosion chamber 19. This flushes the chamber 19 of the burnt gases and iills it With the fresh charge which is then compressed upon the return movement of the piston and exploded.

' Washer 229 on said plunger.

Referring noW to the mixing chamber and valve 17 therein, it should be stated that the supply of gas through pipe l() is usually controlled by any ordinary type of governor (not shown) but, even With such a governor for the normal gas supply, .it will fbe Vvapparent that When vthe engine is @operating in locations Where gas or gasoline vapors are present in the atmosphere such vapors cangain access to -the engine 'cylinder "through airsupply pipe 13 so that l'the'speed of the engine will become abnormal or, as before mentioned, may continueto operate even thoughthe normalA gas supply has been-cut oi by .the governor or the spark rendered inoperative.

Eer these reasons, vmeans Aare zprovi'ded .in the present .instance Vfor closing kboth 'ports 14 and 16 Whenever the engine operatesabove a predetermined speed. 'Suchmeans vpreferably consist of a `plunger 2.5 .slidablysecured inra screw plug .26 in'fcover A27 ofthe mixing chamber,the inner end of -saidplunger being alined With, but normally fheld spaced slightly 'ro1n,'valve stem `18by;a spring 28 seated in said screw plug and engaging a collar .or At its exterior end plunger has a nut or head 30 adjustable longitudinallyithereof and immedi- .ately above said head is a cam 31 rotatable on a horizontal axis, being mounted on a shaftf32 journaled iniarms33foia bracket 34 mounted on cover 226.

Gainilicarriesra Weightediarm 35 Which is normally rheltl by a screvv :36 in bracket 34 a'bove the icam :and just :to 'one side oaf the vertical plane in Whichzshait 32 is located-so that .Wheniabnormal vibrationszarecreated by the fenginezoperatin'g `inieXcess of .a predetermined ':speed,=armf`35 will :be ari-edi or moved pastfsaid verticalrplanie andidropf onthe opposite'sidefof':saidplane byrgravity. Thismovement of said .arm will rotate cam 31'and de- `press plunger125 so .that thedatter, by `aengagement with valve stem 18, ywill zprevent ivalve '17 opening. In fthis vivay niotliiiig, feither air or gas,-or an airtgas mixture, can gain access .to the oylinderfthroughthefair oi-.gas .pipes -10,i13. In tl1is'\Way,`the`flo-W of explosive miritures to 'the explosion -ichamber isautomatically ,cut-off When theiengine exceeds 'apredetermined -sp'eed and 'the engine Acannot be agaiir operated @until arm 35 iis lmanually ele- -vatedl positions `ofthe*severalgparts may `be so `regulated y as -to .render xthe mechanism veny sensitive-to the vibrations of' the-engine.

nWhat I claim is.:

vgravity upon operation of the engine above a predetermined speed. j Y Y 2. LI'nan actuating mechanism orthevalve controlling thesupply-'ot' fuel 4to an engine, Ythe combination ofa .reciprocatory support -for said valve adapted to reciprocate to open land .close said valve,.a plunger normally disengaged rom said reciprocatory support, and a ipivoted armoperable yby the vibrations of the engine dior actuating said plunger ito fengave said reciprocatory vsupport and lmove the valve to its closed positions when the engineoperates abovea predetermined speed.

3. .i[*n:an actuating mechanism ifor .a `valve controlling 'the `fuel supply f of an engine, fthe combination of Aa reciprocatory support .for said valve and adapted'to reciprocate toopen and close said '-valfve, .a plunger V:normally disengaged rom said :reciproeatory support, a cam lrotatable about 'a lhorizontal axis .adjaeentione end offsaid plungenand anarm carried -by said acam normally "positioned to `one side zof Athe lvertical plane of theaxis of frotation of -said cam fand .adapted to be imoved past Asaid vertical .fplane by `vibrations of rthe engine 'when `,the 'latter loperates above Ja vpredeterminedispeedamovemeaitiofasaid. arm'permittingitto fallbyjgravity and rotate said cam ito .reciprocate said iplimger and valve support. l

f4. .fn an .actuating mechanism or'the'valve controlling the supply r.of .fuel to gan engine,

the combination :ofza :reciprocatory support for vsaid-vailveiadapted-to reciprocate to "open and close '.-said valve, ya :plunger normally idifsengaged from said reciprocatory support, 'a cani rotatable vabout .a 'horizontal axis adjacent one end of'saidplungeigand an arm carried fiby said lcam :normally 1 positioned .to one side :ofthe vertical plane of the axis of rotation eof said ycam and adapted to vbe moved lpast said vertical I'plane by y[vibrations of ithe fengine AWhen fthe latter operates f above a prede'termined speed, movement of said arm permitting it'to fallby gravity andfrotate said cam to reciprocate l'said 4plunger and valvecsupport, anduneans 'for adj ustably varying the :normal position of saidfarm AWithrespect .tofsa'id k'vertical plane.

.5. fln anactuating mechanismfor the valve controlling the supply of fuel fto an engine, the combination of la reciprocatory support .for'said 'valve andadaptedto yreciprocate to open and close said valve, a plunger normally .disengaged from said recipro'catory support, a cam .rotatable about Va horizontal aXisadl] ace nt one end of .said ,plunger,.means for .ad- Justing said ,plunger with respect to th'e ycam surface of said cam, and an arm carried by said cam normally positioned to one side of the vertical plane of the axis of rotation of y said cam and adapted to be moved past said vertical plane by vibrations of the engine When the latter operates above a predetermined speed, movement of said arm permitting it to fall by gravity and rotate said cam to reciprocate said plunger and Valve support.

6. In an actuating mechanism for the valve controlling the supply of fuel to an engine, the combination of a reciprocatory Valve stem on which said valve is mounted, a plunger, a spring yieldingly holding one end of said plunger spaced from said valve stem, a cam rotatable about a horizontal axis at the opposite end of said plunger, and a weighted arm carried by said cam and normally held in substantially vertical position above said cam and to one side of the axis of rotation thereof, said arm being free to be moved past said axis of rotation by vibrations of the engine when the latter operates above a predetermined speed whereby said cam Will be rotated to actuate said plunger and valve stem and move the valve to its closed position.

MAXWELL K. BARNARD. 

